Guests are being invited to stay at "hotel influenza" in St. Louis, and they are even being offered payment for their stay. The catch? Visitors must be exposed to the flu.

Researchers from St. Louis University are offering a 10- to 12-day stay to test the effectiveness of flu vaccines. Volunteers will be given either a flu shot or a placebo, and then given a dose of the flu virus through a nasal spray, according to the St. Louis Post-Dispatch.

Participants will be monitored around the clock in the quarantined hotel where they will receive catered meals. Anybody who comes down with the flu must test negative for the virus for two days before checking out.

The university spent about $350,000 to convert the former Water Tower Inn into the 24 room Salus Center. They hope to welcome guests within the next year.

Volunteers will receive $3,500 for their participation and will have any necessary medical costs covered. Guests will also have access to TV, internet, a gym and views of the Arch during their stay.